The port fails to build due to unrecognized compiler command line arguments -mcrypto and -mvsx. I am building on a Mac Mini G4 running FreeBSD 12.1-RELEASE and a freshly updated ports tree as of January 4, 2020 at 20:00 AST.
The failure is probably related to the same root cause as (a portion of) bug 242521. In that case, the solution was to switch from base cc to GCC9. However, the change was only applied for powerpc64; the same compiler complaints also apply to 32-bit powerpc.
Repeating the build with USE_GCC=9 yields a successful result.
I suggest that the port should be updated to automatically choose gcc9 instead of base gcc4.2 for the 32-bit powerpc architecture as well.